Improvement in rotary steam-engines



yJ. P. BROWN. Rotary Steam-Engine.

- No. 205,048.-A Pafenfed1une18y1878..

III@

WI Inf M W1 TJ-VJfSSES. am

UNITED STATESPATENT OFFICE.

JOHN F. BROWN, OF INDIANAPOLIS, INDIANA.

IMPROVEMENT IN ROTARY STEAM-ENGINES.

Specication forming part of Letters Patent No. 205,043, dated June 18,1878; application led April 29, 1818.

To all whom it may concern:

Be it known that I, JOHN F. BROWN, of the d city of Indianapolis, countyof Marion, and

State of Indiana, have invented certain new and useful Improvements inRotary Steam- Engines, of which the following is a specification:

Reference is had to the accompanying drawings, which are made a parthereof, and on which similar letters of reference indicate similarparts.

Figure 1 is a side elevation, partly in section, of an en gine in whichmy invention is embodied. Fig. 2 is a transverse vertical sectionthereof on the dotted line x av,- and Fig. 3 is a horizontal or plansectional view of the cut-off valve, by means of which the admission ofsteam into the hollow shaft is regulated.

In said drawings, the portion marked A is the bed-plate or lowerframe-work to which the cylinder is attached. B B are the pillowblocks,on which are the bearings for'the piston-shaft E. O is the cylinder,which is primarily of a plain tubular form, and preferably open at bothends. D is the piston, which consists of two or more eccentrically-setcylinders, d d d, divided and inclosed by iianges d* d* and cl2 d2, allof which are secured upon a common shaft, E,which runs through andprojects beyond them and rests in suitable bearings on thepillow-blocks.

The pistons d d d are of a considerably less size than the internaldiameter of the cylinder C, but are set upon the shaft E eccentrically,so that one side thereof shall be in constant contact with the inside ofsaid cylinder as they rotate with the shaft. The flanges dl d1, and alsod2, are of the same size as the internal diameter of the cylinder O, andare set concentrically upon the shaft, so that every part of theirperipheral surfaces shall be in constant contact with the inside of saidcylinder, and thus divide it into several inclosed chambers. Thepistons, iianges, and shaft will usually all be formed from a singlepiece of metal, as shown in the drawing; but should so large a size bebuilt as to render this impracticable the parts will be divided, asshown by the dotted lines. The flanges d2 cl2 serve as the usualcylinder-heads, and renderthe takin g apart of the engine exceedinglyeasy. However, if the usual heads are thought desirable, they can beapplied, and the anges in that case can either be retained or dispensedwith at pleasure.

The shaft E is made hollow, thus forming the supply-pipe through whichthe steam reaches the ports in the pistons. Leading from this pipe outthrough the larger side of each of the pistons, and just to one side ofwhere they come in contact with the cylinder, is one or more ports, c c,through which the steam enters the cylinder. I is a cut-off valve,through which the steam is admitted to the hollow shaft. This valve iscomposed of the hollow plug il (which is firmly attached to the shaft E,of which it forms a continuation) and the T-shaped fitting i2, attachedto the pipe H, which approaches the valve at right angles with the lineof the shaft. From one side of the hollow plug t" enough of itssubstance is cut away to form an opening to its center sufficient insize in one direction to admit steam the proper length of time and tothe proper quantity. and in the other to match the opening in the pipeH. As the shaft revolves the remaining portion of the periphery of thisplug acts as a cut-off. The outer end of this plug is threaded, andbears upon it the nut t3 and the washer i4, by which atightly-iittingjoint is secured.

As the steam passes into the cylinder through the ports c c it impingesagainst the abutments J J and thus forces the pistons forward. Theseabutments are jointed to the outside of the cylinder through the sidesof which they pass, and are held in contact with the pistons by thesprings KK. They are made to fit closely against the steam sides of theopenings in the cylinder, but are left loose on the other side, and arealso provided with eX- haust-ports j j, through which the dead steamescapes.

Instead of swinging abutments those that slide may be substituted, andinstead of the springs K K other mechanical contrivances may be used.

No packing-rings or means of conveying away exhaust-steam are indicatedin this specication or are shown in the accompanying drawings, for someform of such devices are common to all engines and are well known tothose skilled in the art. I therefore do not desire to confine myself toany particular form, but wish to leave such points, as well as manyother details of construction, with the builders who may manufacturethem.

My invention consists, first, in the construction of a rotary enginehaving` two or more cylindrical pistons eccentrically set on a commonshaft, in combination with abutments against which the steam shallimpinge; secondly, in the dividing of the cylinder of such an en gineYinto several pressure-chambers, the steam in each of which shall act onthe diametricallyopposite side of the piston-shaft from that in thenext, thus neutralizing the side friction of the pistons against thecylinder which would exist if the steam pressure was all on one side;thirdly, in the admitting steam into such an engine centrally by meansof ports in the pistons, and discharging it. circumferentially by meansof ports in the sides of the cylinder; and, fourthly, in constructing asuitable cut-oit' valve for such an engine.

It will also be seen that in this engine each piston will take steam butonce in an entire revolution.

In practice I divide the cylinder into three chambers by means of theanges 'di d1, and construct a piston for each. I make the central pistonequal in size to both of the others, and place it diametrically oppositeto them on 1. The shaft E, concentrically-set iianges d1 and d2, andeccentrically-set pistons d d d, together forming the device D, incombination with the cylinder C, substantially as shown and specified.

2. The combination of the hollow shaft E,

having steam-ports c c, the flanges dl d1 and d2 d2 inclosing anddividing the pressure-chambers, the pistons ddd and the cylinder'O,having suitable exhaust-ports, forming a rotary steamengine,substantially as shown and specified.

In Witness whereof I have hereunto set my hand and seal at Indianapolis,Indiana, this 24th day of April, A. D. 1878.

JOHN i F. BROWN. [L.

In presence of- C. BRADFORD, FRANK D. BoRNHoLT.

